Brake for electric cars



(N0 Model.)

B. L. RANDALL. BRAKE P011 31.1101111111 0411s.

. No. 444,110. Patented Jan. 6, 1891.

wif/www, L 52W/25m UNITED STATES PATENT OFFICE.

BELLYILLE L. RANDALL, OF BOSTON, MASSACHUSETTS.

BRAKE FOR ELECTRIC CARS.

SPECIFICATION forming` part of Letters Patent No. 444,110, dated January 6, 1891.

Application filed September 11, 1890. Serial No. 364,625. (No model.)

To @ZZ whom t may concern:

Be it known that I, BELLvILLE L. RANnALL, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Oar-Brakes; and I do hereby declare the following to be a full, clear,

, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, ret'- erence being had to Ythe accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

This invention relates to car-brakes, particularly those applied on cars in which electricity is employed as the motive power.

My improvements consist in such mechanism as willen able the driver of an electric car, when he applies the brake, to automatically and simultaneously cut olf the power. Thus, since any application of the brake necessarily calls for a diminution of the motive power, the driver is not obliged to direct a thought to the act of shutting off the power, but merely applies the brake to suit an emergency. This shutting off of the current is governed directly by the action of the brake-that is, the

harder the latter is applied the more quickly.

is the motive power reduced or rendered nothing. 1

The drawings represent in Figure 1 a plan of a brake embodying my invention applied to an electric car. Fig. 2 is a vertical section through the power and brake drums. Fig. 3 is an enlarged View in plan of the brake and power drums, showing the position of the engaging lugs when the brakes are off and the power not applied.

In the drawings accompanying this specification I have represented in plan one end of a street-car 2, with the usual girders and tie rods, the iioor being removed. Since the ends -of this class of cars are duplicates in construction, but one end is shown for purposes of illustration. On the front end and exteriorly of the dasher 3 are mounted two shafts or rods 4 5, furnished with suitable hand-levers or cranks (not shown) by which they are revolved. These rods are termed, respectively, the power and brake rods, since by means of the former the current or amount of force put in action is regulated. By the latter the friction applied to the wheels is controlled. In connection with the powerrod is a switch 6 for directing the current in order to advance or to back the car. Furthermore, beneath the car and suitably mounted is a pendent shaft 8, upon which is loosely affixed a revoluble drum, (indicated at 9 as the upper one, and styled the brake-drum, since it is connected by a chain or band 10 with the brake-rod.) Exterior] y of said shaft is placed a loose sleeve 12, upon which is fastened a second drum 13, similar to that represented at 9, and which is termed the power-drum, the latter being actuated by the power-rod through the agency of`a band or chain 14 and serves to control the speed of the car. This result is obtained as follows: A radial arm or lever 15 is secured to the sleeve l2 and by the motion of the latter, produced by the drum and the operation of the band 14, is caused to co-operate with a rheostat, (indicated at 16.) This apparatus is attached at the end of the shaft 8, which supports it.

The resistances of the above mechanism can be thrown in and out of the main circuit with the evident result of regulating the amount of current flowing therein. This lever 15 swings in a horizontal plane and moves over the various contact-segments composing the rheostat. However this forms no part of my invention, and any further description will be unnecessary.

The primary object of my invention is to control the motive power by means of the brake, while at the same time not prevent the power-rod from exercising its usual function. To accomplish this result, I have connected the brake-rod 5 by means of an endless band or chain 10 with the brake-drum and, moreover, secured an abutment 17 on its lower side. This abutment is adapted to contact with a corresponding ledge -or shoulder 18 upon the upper side of the power-drum. As a result, it is evident that rotation of the brake-rod to set the brakes will likewise revolve the brakedrum and cause the power-drum to be operated, swinging the lever-arm 15 to create such resistance on the rheostat as will effectually check the current. Thus simultaneously with the application of the brake the motive power ICO is diminished, and hence in a case ol emergeney the attention of the driver is not divertcd, in order to tirst cut ott the power and then set the brake.

It is to be understood that the position ot the brake-drum and its lug are such that no movement ot the power-drum occursl unless the power is applied; but should the power he applied thelug 1S on the power-drum is then in position to be engaged by the lug on the brake-drum when the rheostat-lever is operated by the rotation of the brake-rod. As soon as the brakes are oft the brake-drum is returned to its normal position, as shown in Fig. 2, in readiness to cut ott the power whenever the brakes are again applied. By such an arrangement it is very evident the powerrod free to move the power-drum and rheostat-lever without interference or hinder-ance bythe brake-drum and its operating` meehanism.

In lfig. .l is shown a modified form of arrangement. In lieu of connecting the brakerod by the chain lOwith the lnake-tlr1nn,the chain l() and the brake-dru1n .l may be omitted, while a band or chain 1S is substituted. This band unites the power and brake rods. 'Io enable the same eil'ect to be produced as hereinbefore described-viz., to shut oft the power by the application ot thebrakes-l have made the band 1S of such length that considerable slack exists, this slack being` taken up by a spring l) or its equivalent. As shown in Fig. l, thepower is shut oft' and the brakes tree. Consequently no part of the chain is wound either aboutthe power-rod or thebrakcrod and the slack is held by the spring 15). Assume that the car is to be started. Rotation ot the power-rod -lcauses one or more turns ol' chain to be made thereabout, and this remains so coiled until the brakes are applied by rotation of the brake-rod. Such movement coils the chain in part about said brakerod and uncoils that about the power-rod, thus actuating the latter, and the same effect is produced as when a brake-drum is used and a chain unites the brake-rod with said drum. Conversely, presuming the power has been shut oit by application ot the brakes, when the latter are released part of the chain wound about the brake-rod is uneoiled, and this slack is taken up by the spring 19. Thus the powcrcanbeapplicdwithoutbeinginflucnced by the brake-rml; but any movement ot' the latter in setting the brakes serves to operate the rheostat-lever and diminishes the power, provided the power is then applied. lhe same result is thus accomplished as by the arrangement ii rst described.

It may he added that the resistance of the spring 19 is sutlicient to cause either the power or brake rods, when the chain is passing about; them, to actuate the mechanism connected with them in lieu ot yielding and permitting the slack to be coiled up without operating the parts intended to be moved. The brake-drum rotates in direction of arrow 1 (see Fig. 3) when the brake is applied, and the power-drum oppositely (sce Fig. 3, arrow 2) when the power-rod is moved to start the motor.

What I claim is- 1. The combination, with the revoluble power-rod, a rheostat, and its lever by which resistanccs are thrown in or out', of a revoluble brake-rod and mechanism, as a chain, by which the rheostat-lever is positively interconnected and operated separately by the power-rod or by the brake-rod, substantially as described.

2. In an electric car, a fixed rheostat, a shaft carrying two revoluble drums, a brakerod and a power-rod respectively operating said drums, means for causing the latter to engage at certain points in their revolution, and a rheostat-lever 'actuated both by the power and by the brake shafts, substantially as herein stated.

3. The combination, with the rotary power and brake rods 4 and 5, of the rod or shaft 8, fixed to the bottom ot the car, the brake and power drums 9 and 13, loosely mounted on said shaft and provided with engaging abutments or shoulders 17 18. the regulating arm or lever 15, connected with the said powerdrum to move therewith, and the bands or chains l0 14, connecting the said brake and power shafts with the said brake and power drums, as set forth.

In testimony whereof Iai'lix my signature in presence ot' two witnesses.

BELLVILLE I..

H. E. Lonen, FnANols C. Stinwooo.

.IADA LIL.

IOO 

